~ Restoration, modification and servicing of wristwatches

A Seiko 6309-7040 Part II

Poised as we are at a stationary point, the transition state between ‘before’ (see part I here) and ‘after’, in the spirit of a downhill run, I’ll keep the verbals to a minimum and let the pictures do the talking.

Case

A thorough clean to the case is all that is required, the case in such nice original condition that any refinishing would really undermine the spirit of this project. Here’s the mid-case with chapter ring and crystal gasket ring fitted

ready for the original crystal gasket, still in excellent condition after 32 years

In the choice of crystal we maintain the purist approach by resisting the temptation to fit a domed 6105 crystal but allow a minor indulgence in opting for a coated flat sapphire manufactured to the same dimensions as the original Hardlex:

and secured to the case with the crystal retaining ring

Let’s turn now to the movement.

Movement

Snags around the barrel hole smoothed away:

main plate Diashock setting

retaining spring fitted

reassembly complicated only by some vacillation over whether to go for the 6319 barrel and train wheel bridge. In the end, the decision was made for me because the third wheel from the 6319 was corroded and the watch failed to run smoothly with it fitted and so I took this as a sign to stick to a 6309 bridge and keep faith with just 17 rather than 21 jewels. I’ll skip most of that in the interests of brevity, pausing though to consider the dial and hands once again:

Dial and Hands

Here’s the calendar side of the movement, reassembled with the dial spacer fitted

with the dial on

we are ready for the hands and need to make another decision. You may recall we have a number of options to choose from, ranging from two sets of original NOS hands, one set of aftermarket, and the original hands which cleaned up quite nicely but which would need reluming. As I fancied having another stab at luming, I thought I’d give it a go and see how they looked before making a decision. The result of that process, after one false start, actually looked really pretty good, the colour match more than good enough:

We are almost ready to put it all back together, only the crown needing a spot of TLC.

Crown and stem

The crown and stem on these dive watches are a two part affair, with the stem moving against a spring, which as you can see looked in a bit of a sorry state

but importantly all of the components there. The gasket was hardened and needed replacing, the rest if the components undergoing a thorough clean before reassembling with a generous dash of silicone grease

ready to take its place together with the movement in the case

The home straight

Winding bridge back in position

and rotor

before closing her up and flipping over ready for the turning ring and bezel

It might be worth pausing at this point to compare the slightly worn original insert, with its characteristic dished aspect and slightly granular finish, with a modern Seiko equivalent taken from an SKX007 as well a low grade aftermarket insert

A fresh bezel gasket and on the turning ring pops to bring the process to its conclusion

All that remains is to fit the strap, held in place with the original 22mm fat spring bars, and give it a spin around the block:

Hi Danny,
If you mean the knurled turning ring itself, then it should be fairly easy to find a used replacement (in fact I have one or two stashed away myself). If you can find one of these plus a fresh gasket, you could then fit a decent quality insert. The photo below shows a turning ring fitted to a 7548 but without the insert fitted.

As far as insert choice is concerned, you can find decent quality aftermarket inserts from a seller called Yobokies or, even better in my opinion, source an original Seiko insert from an SKX007 and modify it to accept an original lume pip. This is what I’ve done here:

If you want a complete original bezel and insert in new condition, then that is going to be very difficult. None of the watch parts houses carry stock any more and I’ve only very occasionally seen them come up on Ebay and only then at quite high prices. There are sellers on Ebay from the Philippines who sell new aftermarket bezel rings with insert but I don’t know what the quality is like. They are cheap enough to give them a try but if it were me, I’d prefer to stick to an original Seiko ring.

Cleaning and oiling a watch movement is not something to be undertaken lightly. You have to dismantle it completely into its constituent parts, clean thoroughly in an ultrasonic bath, preferably using watchmakers cleaning solutions, and then reassemble, paying attention to the correct oiling using the correct lubricants. The investment required to assemble the tools and consumables to do that would be quite considerably more than the cost of getting your watch serviced by a watchmaker. But to answer your question, I routinely use 6 or 7 different types of watchmakers lubricants depending on the application. These are very fine quality oils and greases designed for their specific roles. The lubricants alone would set you back at least $90US if you took a minimalistic approach and probably half as much again if you bought the same set that I use.

hello sir nice article here very informative and good read.
i got into this site because i have one concern regarding my skx007j which i recently bought and maybe you will be able to help.
The crown in my watch was very stiff and having difficulty in unscrewing and screwing in so i made research. after researching one trick i found was to unscrew the crown all the way to position 2 (adjusting time) and wrap the threads with floss, then screw the crown back in. Next step obviously is to unscrew the crown and pull the floss. This way, the threads are cleaned with some dirt. Surprisingly the trick worked. However, upon pulling the floss, i noticed it was torn. my concern now is, is there any chance that a part of the floss may be left in the crown? and will it be able to reach the watch mechanism? i have no tools to open my watch and i haven’t tried opening watch so i am not comfortable opening it. your help is much appreciated.
Thanks in advance!

Ray, I think you are probably ok as far as worries of any thread remnants making their way into the watch because the crown o-ring seal sits inside the case tube on these watches. The only way to be sure there is nothing left ensnared in the crown threads is to open the case and remove the crown and stem. So you can choose to leave it alone and not worry about it, take it to a watchmaker to have the crown cleaned out or take a couple of brave pills, buy a watch case back opener and give it a try yourself. If you are uncomfortable doing the latter then you are left with options 1 and 2. Good luck!

Thanks Martin. Yeah eventually i will try to open this watch, im just kind of hesitant now as it is brand new. In the meantime, i will try not to worry about it and trust the o-ring to protect things from getting into the watch. Thanks again for your advice. Cheers!

Ed, I’m afraid I am not a professional watchmaker – just a hobbyist and don’t take in work. However, I see that you are in the UK and I would recommend you give either Richard Askham a try (thewatchspotblog) or Duncan Hewitt (thewatchbloke). Both very experienced with vintage Seiko.

Hi Martin: I have a 6309-7040 which was the first watch that I bought back in 1980 and wanted to know if you can recommend a reputable repair shop that does quality lumens rework. I googled and saw a place located in Detroit but being on the West Coast In the San Francisco Bay Area would prefer somewhere closer. Any recon would be most appreciated as I still wear this watch almost every day..

Hi Richard, I’ll be honest and say that I don’t know of anyone currently in the USA to whom I would send a watch for a relume. My experience has usually been one of disappointment in the work of professional relumers. If you need someone to service your watch then you might give Spencer Klein in Colorado a try. He has a YouTube channel and a website. I have no personal experience of his work but he is a proper Seiko enthusiast. Good luck!